André C, Duy S V, Sauvé S, Gagné F
Aquatic Contaminants Research Division, Environment and Climate Change Canada, Montréal, QC, Canada.
Chemistry Department, Montreal University, Montréal, QC, Canada.
Front Physiol. 2023 Aug 10;14:1233659. doi: 10.3389/fphys.2023.1233659. eCollection 2023.
Municipal effluents are well-recognized as disrupting sexual differentiation and reproduction in mussels. However, the contribution to this problem made by rainfall combined with sewer overflow (increased by rain due to climate change) is not well understood. The purpose of this study was to compare the neuroendocrine effects of municipal discharge and rainfall overflow on caged endemic mussel . To this end, mussels were experimentally caged and placed for 3 months at a municipal effluent dispersion plume site and at overflow sites. Data revealed that downstream surface water contained some pharmaceuticals (caffeine and carbamazepine) and accumulated significant levels of heterotrophic bacteria, but these effects were not observed at the overflow sites. The principal effects observed at the downstream site were increased soft tissue mass (and gonad index), inflammation, and Vtg proteins in male mussels as determined by a novel immunostaining methodology. The rainfall overflow sites had no effects on these markers, but were specifically associated with reduced Vtg proteins in females, dopamine (Dop), gonad lipids, and DNA strand breaks, with increased metallothioneins. In conclusion, the observed feminizing effects of municipal effluent were not additionally observed in mussels caged at rainfall overflow sites, although the latter exhibited a different pattern of toxicity.
城市污水被公认为会干扰贻贝的性别分化和繁殖。然而，降雨与下水道溢流（因气候变化导致降雨增加）对这一问题的影响尚未得到充分了解。本研究的目的是比较城市排放和降雨溢流对圈养本地贻贝的神经内分泌影响。为此，将贻贝进行实验性圈养，并在城市污水扩散羽流站点和溢流站点放置3个月。数据显示，下游地表水含有一些药物（咖啡因和卡马西平），并积累了大量异养细菌，但在溢流站点未观察到这些影响。通过一种新型免疫染色方法测定，在下游站点观察到的主要影响是雄性贻贝的软组织质量（和性腺指数）增加、炎症以及Vtg蛋白增加。降雨溢流站点对这些指标没有影响，但与雌性贻贝中Vtg蛋白减少、多巴胺（Dop）、性腺脂质和DNA链断裂减少以及金属硫蛋白增加有特定关联。总之，在降雨溢流站点圈养的贻贝中未额外观察到城市污水所观察到的雌性化影响，尽管后者表现出不同的毒性模式。
